The invention relates generally to wireless communication systems and more particularly to a system and method of reducing interference in a wireless multiple-input-multiple-output (MIMO) system.
In a cellular system, a basestation is uniquely associated with each cell. Each basestation communicates with mobile stations within its associated cell. In one embodiment, a cell defines a geographical area. With MIMO systems, different data signals can be sent from multiple transmitting antenna elements at a transmitter (e.g., a basestation) to multiple receiving antenna elements at a receiver (e.g., a mobile station). Such MIMO systems can increase the data capacity of a cellular system over the data capacity of a non-MIMO based system.
Interference with a desired signal, however, can result at a receiver when undesired signals are also received. In a cellular system, a receiver can receive signals both from a desired transmitter (e.g., the basestation within the same cell) and undesired transmitters (e.g., basestations from neighboring cells), thereby resulting in interference. Simulations have shown that in interference-limited environments, the capacity of MIMO systems may not be larger than the capacity of systems with multiple antennas at one link end only.
Thus, an improved system and method is needed to reduce the interference caused by multiple transmissions received by a receiver in a MIMO system.